The inventive concept relates generally to image processing devices and methods for processing image signal(s). More particularly, the inventive concept relates to image processing devices capable of processing multiple image streams having different respective resolutions, as well as image processing methods used in such image processing devices.
The term “image sensor” is used to denote a class of electronic devices that capture a visual image and convert the captured image into a corresponding electrical signal. Image sensors are used not only in general consumer electronics, such as digital cameras, mobile phone cameras, and portable camcorders, but also in vehicles, security devices, robots, etc. The CMOS (complementary metal-oxide semiconductor) image sensor is one type of image sensor commonly used in contemporary products. The CMOS image sensor includes a pixel array, wherein each pixel includes a light sensing device. Each light sensing device is configured to generate an analog electrical signal corresponding to the intensity of light received (or absorbed) by the light sensing device. Hereafter, the light received by a light sensing device will be termed “incident light”.
An image signal processor (ISP) processes the analog electrical signal(s) provided by one or more light sensing devices of an image sensor by converting the analog electrical signal(s) into corresponding digital data. An ISP may be configured for this purpose and disposed within a variety of devices, such as mobile devices (e.g., smart phones, tablets, etc.).
In certain operative configurations, an ISP may be required to simultaneously process dual image streams, where one image stream has a relatively lower resolution than the other. For example, a mobile device may include two (or more) camera modules, each having a different respective resolution. Thus, a single ISP incorporated in the mobile device may be required to rapidly process both a low-resolution image stream and a high-resolution image stream. However, address the potential requirement of simultaneously processing the low-resolution image stream and high-resolution image stream, the constituent ISP must operate with a sufficiently high processing speed and processing capacity to acceptably process the high-resolution image stream. As a result of this necessity, the ISP must provide a line buffer and/or a kernel size sufficiently large to accommodate the high-resolution image processing requirement. Power consumption by the ISP may also be adversely influenced by the high-resolution image processing requirement.